In ophthalmic surgery, and in particular in vitreo-retinal surgery, it is desirable to use a wide-angle surgical microscope system to view as large a portion of the retina as possible. Wide-angle objective lenses for such microscopic systems exist, but they require a wider illumination field than that provided by the cone of illumination of a typical fiber-optic probe. As a result, various technologies have been developed to increase the beam spreading of the relatively incoherent light provided by a fiber-optic illuminator. These known wide-angle endoilluminators can thus illuminate a larger portion of the retina as required by current wide-angle surgical microscope systems.
While it is generally desirable to illuminate (view) as large a portion of an ophthalmic surgical field as possible, it is also desirable at certain points during a surgical procedure to provide a more precise spotlight to show fine details. Prior art solutions exist to provide both general illumination of a surgical field and its peripheral areas and spot illumination of a smaller area. These prior art solutions, however, suffer from the disadvantage of needing more than one instrument to provide such dual lighting capability.
For example, prior art solutions include providing illumination to peripheral areas of a surgical field via one entry site into the eye, while providing spot illumination with a standard fiber optic probe inserted via a different entry site. Another solution for providing peripheral lighting has been to insert a chandelier probe via, potentially, yet another entry site into the eye. Proper lighting of a surgical field has thus typically required multiple incisions to provide entry points into the eye for multiple illuminators. It is generally desirable to limit the number incisions on an eye during surgery.
Separate peripheral (general) lighting of a surgical field is required because a standard fiber optic probe, typically housed in a metal cannula, cannot provide such peripheral lighting, and a wide-angle illuminator, while capable of providing a broader range of illumination, cannot provide a precise spotlight to illuminate finer details of a surgical site, as can a standard fiber optic illuminator. Thus, no single prior art endoilluminator has been developed that can provide, alternatively, diffuse light to provide general illumination of a surgical field and peripheral areas and a precise spotlight to illuminate a smaller area to show greater detail.
Therefore, a need exists for a surgical variable intensity endoilluminator that can reduce or eliminate these and other problems associated with prior art illuminators.